Exhaust duct



FIG. 1 is a perspective view of the duct;

FIG. 2 is a top view of the duct;

FIG. 3 is a bottom view of the duct;

FIG. 4 is a side view of the duct;

FIG. 5 is a rear view of the duct; and,

FIG. 6 is a front view of the duct. 

The ornamental design for the exhaust duct, as shown. 